[posix.cfg] Fix fstat family (#2629)

* [posix.cfg] Fix fstat family
* Move fstatat64 and __fxstatat64 to gnu.cfg

Author: martong

cfg/gnu.cfg

@@ -1320,6 +1320,54 @@
       <not-bool/>
     </arg>
   </function>
+  <!-- Note: fstatat64() is a large-file version of the fstatat() function -->
+  <!-- int fstatat64(int dirfd, const char *pathname, struct stat64  *statbuf, int flags); -->
+  <function name="fstatat64">
+    <noreturn>false</noreturn>
+    <leak-ignore/>
+    <returnValue type="int"/>
+    <arg nr="1" direction="in">
+      <not-uninit/>
+      <valid>0:</valid>
+    </arg>
+    <arg nr="2" direction="in">
+      <not-null/>
+      <not-uninit/>
+    </arg>
+    <arg nr="3" direction="out">
+      <not-null/>
+      <not-bool/>
+    </arg>
+    <arg nr="4" direction="in">
+      <not-bool/>
+      <not-uninit/>
+    </arg>
+  </function>
+  <!-- int __fxstatat64 (int __ver, int __fildes, const char *__filename, struct stat64 *__stat_buf, int __flag); -->
+  <function name="__fxstatat64">
+    <noreturn>false</noreturn>
+    <leak-ignore/>
+    <returnValue type="int"/>
+    <arg nr="1" direction="in">
+      <not-uninit/>
+    </arg>
+    <arg nr="2" direction="in">
+      <not-uninit/>
+      <valid>0:</valid>
+    </arg>
+    <arg nr="3" direction="in">
+      <not-null/>
+      <not-uninit/>
+    </arg>
+    <arg nr="4" direction="out">
+      <not-null/>
+      <not-bool/>
+    </arg>
+    <arg nr="5" direction="in">
+      <not-bool/>
+      <not-uninit/>
+    </arg>
+  </function>
   <!-- ########## Resource allocation ########## -->
   <resource>
     <alloc init="true">mkostemp</alloc>

cfg/posix.cfg

@@ -1400,13 +1400,13 @@ The function 'mktemp' is considered to be dangerous due to race conditions and s
       <not-bool/>
     </arg>
   </function>
-  <!-- int fstat(const char *file_name, struct stat *buf); -->
+  <!-- int fstat(int fd, struct stat *statbuf); -->
   <function name="fstat">
     <noreturn>false</noreturn>
     <leak-ignore/>
     <returnValue type="int"/>
     <arg nr="1" direction="in">
-      <not-null/>
+      <valid>0:</valid>
       <not-uninit/>
     </arg>
     <arg nr="2" direction="out">
@@ -1415,15 +1415,13 @@ The function 'mktemp' is considered to be dangerous due to race conditions and s
     </arg>
   </function>
   <!-- int fstatat(int dirfd, const char *pathname, struct stat *statbuf, int flags); -->
-  <!-- Note: fstatat64() is a large-file version of the fstatat() function as defined in POSIX 1003.1-2008 (ISO/IEC 9945-2009). -->
-  <!-- int fstatat64(int dirfd, const char *pathname, struct stat64  *statbuf, int flags); -->
-  <!-- int __fxstatat64(int dirfd, const char *pathname, struct stat64  *statbuf, int flags); -->
-  <function name="fstatat,fstatat64,__fxstatat64">
+  <function name="fstatat">
     <noreturn>false</noreturn>
     <leak-ignore/>
     <returnValue type="int"/>
     <arg nr="1" direction="in">
       <not-uninit/>
+      <valid>0:</valid>
     </arg>
     <arg nr="2" direction="in">
       <not-null/>